Serum vascular endothelial growth factor levels are elevated in metastatic differentiated thyroid cancer but not increased by short-term TSH stimulation

Development and validation of a nomogram to predict cancer-specific survival in elderly patients with papillary thyroid carcinoma: a population-based study

Objective

Thyroid carcinoma (TC) is the most common endocrine tumor in the human body. Papillary thyroid carcinoma (PTC) accounts for more than 80% of thyroid cancers. Accurate prediction of elderly PTC can help reduce the mortality of patients. We aimed to construct a nomogram predicting cancer-specific survival (CSS) in elderly patients with PTC.

Methods

Patient information was downloaded from the Surveillance, Epidemiology, and End Results (SEER) program. Univariate and multivariate Cox regression models were used to screen the independent risk factors for patients with PTC. The nomogram of elderly patients with PTC was constructed based on the multivariate Cox regression model. We used the concordance index (C-index), the area under the receiver operating characteristic curve (AUC) and the calibration curve to test the accuracy and discrimination of the prediction model. Decision curve analysis (DCA) was used to test the clinical value of the model.

Results

A total of 14,138 elderly patients with PTC were included in this study. Patients from 2004 to 2015 were randomly divided into a training set (N = 7379) and a validation set (N = 3141), and data from 2016 to 2018 were divided into an external validation set (N = 3618). Proportional sub-distribution hazard model showed that age, sex, tumor size, histological grade, TNM stage, surgery and chemotherapy were independent risk factors for prognosis. In the training set, validation set and external validation set, the C-index was 0.87(95%CI: 0.852–0.888), 0.891(95%CI: 0.866–0.916) and 0.931(95%CI:0.894–0.968), respectively, indicating that the nomogram had good discrimination. Calibration curves and AUC suggest that the prediction model has good discrimination and accuracy.

Conclusions

We constructed a new nomogram to predict CSS in elderly patients with PTC. Internal cross-validation and external validation indicate that the model has good discrimination and accuracy. The predictive model can help doctors and patients make clinical decisions.

Sorafenib in Metastatic Papillary Thyroid Carcinoma with BRAF K601E Mutation on Liquid Biopsy: A Case Report and Literature Review

Differentiated thyroid cancer (DTC) includes papillary and follicular carcinomas and is the most common type of thyroid cancer. The incidence of this cancer has increased in the last few years, and even if its prognosis is generally good for a subset of patients that does not respond to radioactive iodine (RAI) therapy, the prognosis is much worse: the median overall survival (OS) from discovery of metastasis is 3–5 years and the 10-year survival rate is only 10%. Several mutations, including RAS or RET, as well as BRAF signaling, are associated with thyroid cancer. Liquid biopsy may be useful in selected patient to identify genomic alterations and thus allowing for a precision medicine approach with target therapy. Sorafenib, an oral multi-kinase inhibitor, can be used in the treatment of DTC. Case presentation: A 77 years old. man with diagnosis of metastatic DTC and evidence of presence of mutation of BRAF K601E on liquid biopsy was treated with sorafenib, showing a good response to the treatment and an improvement in the quality of life (QoL). Currently, this patient is still on treatment with sorafenib, gaining control of a multi-metastatic disease, generally characterized by a very poor prognosis. In conclusion, sorafenib has an active role in the treatment of DTC. It also has been considered the standard of care for patients with advanced unresectable hepatocellular carcinoma (HCC) and renal cell carcinoma (RCC). In our case we observe the efficacy of using sorafenib in Papillary thyroid carcinoma (PTC) such as confirming both stable disease (SD) in the CT scan as clinical benefit with an increase in QoL. Therefore, use of sorafenib remains an important treatment option, even in case of BRAF mutation, despite a rapidly evolving treatment landscape. It also seems important to perform liquid biopsies, especially in patients in whom it is not possible to repeat a new tissue biopsy. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in DTC and HCC.

Identification of soluble tissue-derived biomarkers from human thyroid tissue explants maintained on a microfluidic device

Although a large cohort of potential biomarkers for thyroid cancer aggressiveness have been tested in various formats in recent years, to the best of our knowledge, thyroglobulin and calcitonin remain the only two established biomarkers associated with thyroid cancer management. Our group has recently validated a novel means of maintaining live, human ex vivo thyroid tissue within a tissue-on-chip format. The present pilot study aimed to interrogate the tissue effluent, containing all the soluble markers released by the tissue samples maintained within the devices' tissue chamber, for the presence of markers potentially associated with thyroid cancer aggressiveness. Culture effluent from tissue samples harvested from 19 individual patients who had undergone thyroidectomy for the treatment of suspected thyroid cancer was assessed, first using a proteome profiler™ angiogenesis array kit. Patients were subcategorised as 'aggressive' if they possessed a minimum of N1b level metastases, whilst 'non-aggressive' samples were T3 or lower without evidence of multifocality; and contralateral healthy thyroid tissue was harvested for comparative studies. Levels of Serpin-F1, vascular endothelial growth factor, Thrombospondin-1 and chemokine (C-C motif) ligand were significantly altered and, thus, were further investigated using ELISA to allow for quantitative analysis. The concentration of serpin-F1 was significantly increased in the effluent of aggressive thyroid cancer tissue when compared with levels released by both non-aggressive and benign samples. The present study demonstrated the usability of microfluidic technology for the analysis of the ex vivo tissue secretome in order to identify novel biomarkers.

Prognostic and Therapeutic Role of Angiogenic Microenvironment in Thyroid Cancer

Simple Summary

Angiogenesis is an essential event for the progression of solid tumors and is promoted by angiogenic cytokines released in the tumor microenvironment by neoplastic and stromal cells. Over the last 20 years, the role of the microenvironment and the implication of several angiogenic factors in tumorigenesis of solid and hematological neoplasms have been widely studied. The tumor microenvironment has also been well-defined for thyroid cancer, clarifying the importance of angiogenesis in cancer progression, spread, and metastasis. Furthermore, recent studies have evaluated the association of circulating angiogenic factors with the clinical outcomes of differentiated thyroid cancer, potentially providing noninvasive, low-cost, and safe tests that can be used in screening, diagnosis, and follow-up. In this review, we highlight the mechanisms of action of these proangiogenic factors and their different molecular pathways, as well as their applications in the treatment and prognosis of thyroid cancer.

Abstract

Thyroid cancer is the most common endocrine malignancy, with a typically favorable prognosis following standard treatments, such as surgical resection and radioiodine therapy. A subset of thyroid cancers progress to refractory/metastatic disease. Understanding how the tumor microenvironment is transformed into an angiogenic microenvironment has a role of primary importance in the aggressive behavior of these neoplasms. During tumor growth and progression, angiogenesis represents a deregulated biological process, and the angiogenic switch, characterized by the formation of new vessels, induces tumor cell proliferation, local invasion, and hematogenous metastases. This evidence has propelled the scientific community’s effort to study a number of molecular pathways (proliferation, cell cycle control, and angiogenic processes), identifying mediators that may represent viable targets for new anticancer treatments. Herein, we sought to review angiogenesis in thyroid cancer and the potential role of proangiogenic cytokines for risk stratification of patients. We also present the current status of treatment of advanced differentiated, medullary, and poorly differentiated thyroid cancers with multiple tyrosine kinase inhibitors, based on the rationale of angiogenesis as a potential therapeutic target.

Thyroid Cancer Stem-Like Cells: From Microenvironmental Niches to Therapeutic Strategies

Thyroid cancer (TC) is the most common endocrine malignancy. Recent progress in thyroid cancer biology revealed a certain degree of intratumoral heterogeneity, highlighting the coexistence of cellular subpopulations with distinct proliferative capacities and differentiation abilities. Among those subpopulations, cancer stem-like cells (CSCs) are hypothesized to drive TC heterogeneity, contributing to its metastatic potential and therapy resistance. CSCs principally exist in tumor areas with specific microenvironmental conditions, the so-called stem cell niches. In particular, in thyroid cancer, CSCs' survival is enhanced in the hypoxic niche, the immune niche, and some areas with specific extracellular matrix composition. In this review, we summarize the current knowledge about thyroid CSCs, the tumoral niches that allow their survival, and the implications for TC therapy.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Correlation of vascular endothelial growth factor and vascular endothelial growth factor receptor-1 levels in serum and thyroid nodules with histopathological and radiological variables

BACKGROUND/AIM:

Vascular endothelial growth factor (VEGF) is a major cytokine in angiogenesis and has a role on aggressivity of various tumors. The expression of VEGF has been shown to increase in differential thyroid cancer. The aim of the study was to evaluate serum and intranodular VEGF (nVEGF) and VEGF receptor-1 (VEGFR-1) levels in patients with thyroid nodules and their relevance to ultrasonographic and pathological results.

MATERIALS AND METHODS:

A total of eighty patients were included in the study. Thyroid fine-needle aspiration biopsies were performed, and the levels of serum and nVEGF and VEGFR-1 were measured. Any possible correlations between serum and nVEGF, VEGFR-1, and biochemical/radiological variables were investigated.

RESULTS:

There were no significant differences between serum VEGF (sVEGF), nVEGF, sVEGFR-1, nVEGFR-1 levels, number of nodules, size of nodules, and benign and malignant ultrasonographic features. sVEGF and nVEGF were higher in malignant or suspicious nodules than that in benign nodules, but did not reach statistical significance (P > 0.05). sVEGFR-1 and nVEGFR-1 levels were higher in hyperthyroid patients than that in euthyroid patients (P < 0.05 and P = 0.003, respectively). nVEGFR-1 level was higher in hypothyroid patients than that in euthyroid patients (P = 0.016). sVEGF level was found to be higher in hyperactive nodules than that in others. Both sVEGFR-1 (P = 0.008) and nVEGF levels (P = 0.01) significantly increased with increasing age. nVEGFR-1 decreased with increasing body mass index (BMI) (P = 0.004).

CONCLUSIONS:

Our study showed the relationships of sVEGF, nVEGF, sVEGFR-1, and nVEGFR-1 levels with age, gender, BMI, and hyperthyroidism. To determine the role of VEGF/VEGFR-1 in thyroid nodules, further studies are required with a large number of patients.

A Systematic Review of Phase II Targeted Therapy Clinical Trials in Anaplastic Thyroid Cancer

Anaplastic thyroid carcinoma (ATC) is a rare, but devastating disease. Despite multimodal approaches combining surgery, chemotherapy and radiation therapy, ATC is associated with a dire prognosis, with a median overall survival of only three to ten months. Novel treatments are thus urgently needed. Recent efforts towards the characterization of the molecular landscape of ATC have led to the identification of pro-oncogenic targetable alterations, lending promise for novel targeted therapeutic approaches. This systematic review summarizes the results of phase II clinical trials of targeted therapy in ATC, providing an overview of efficacy and safety profiles. The majority of trials to date have consisted of small single-arm studies and have presented modest results. However, only a minority of trials have selected or stratified patients by molecular alterations. In the setting of BRAF V600E mutated ATC, dabrafenib/trametinib combination therapy and vemurafenib monotherapy have both demonstrated efficacy. Everolimus has furthermore shown promising results in patients with PI3K/mTOR/AKT pathway alterations. These studies underscore the importance of molecular profiling of tumors for appropriate patient selection and determination of genomic correlates of response. Clinical trials are underway testing additional targeted therapies as monotherapy, or as a part of multimodal treatment, and in combination with immunotherapy.

Real Microgravity Influences the Cytoskeleton and Focal Adhesions in Human Breast Cancer Cells

With the increasing number of spaceflights, it is crucial to understand the changes occurring in human cells exposed to real microgravity (r-µg) conditions. We tested the effect of r-µg on MCF-7 breast cancer cells with the objective to investigate cytoskeletal alterations and early changes in the gene expression of factors belonging to the cytoskeleton, extracellular matrix, focal adhesion, and cytokines. In the Technische Experimente unter Schwerelosigkeit (TEXUS) 54 rocket mission, we had the opportunity to conduct our experiment during 6 min of r-µg and focused on cytoskeletal alterations of MCF-7 breast cancer cells expressing the Lifeact-GFP marker protein for the visualization of F-actin as well as the mCherry-tubulin fusion protein using the Fluorescence Microscopy Analysis System (FLUMIAS) for fast live-cell imaging under r-µg. Moreover, in a second mission we investigated changes in RNA transcription and morphology in breast cancer cells exposed to parabolic flight (PF) maneuvers (31st Deutsches Zentrum für Luft- und Raumfahrt (DLR) PF campaign). The MCF-7 cells showed a rearrangement of the F-actin and tubulin with holes, accumulations in the tubulin network, and the appearance of filopodia- and lamellipodia-like structures in the F-actin cytoskeleton shortly after the beginning of the r-µg period. PF maneuvers induced an early up-regulation of KRT8, RDX, TIMP1, CXCL8 mRNAs, and a down-regulation of VCL after the first parabola. E-cadherin protein was significantly reduced and is involved in cell adhesion processes, and plays a significant role in tumorigenesis. Changes in the E-cadherin protein synthesis can lead to tumor progression. Pathway analyses indicate that VCL protein has an activating effect on CDH1. In conclusion, live-cell imaging visualized similar changes as those occurring in thyroid cancer cells in r-µg. This result indicates the presence of a common mechanism of gravity perception and sensation.

The roles and role-players in thyroid cancer angiogenesis

Thyroid cancer is the most prevalent endocrine cancer worldwide. Angiogenesis, the formation of new blood vessels, plays a pivotal role in the development and progression of tumors. Over the past years, cancer research has focused on the ability of tumors to induce newly formed blood vessel, because tumor growth and the process of cancer metastasis mainly depends on angiogenesis. Tumor neovascularization occurs following the imbalance between pro-angiogenic and anti-angiogenic factors until the tumor switches to an angiogenic phenotype. A number of signaling factors and receptors that are implicated in the regulation of angiogenesis have been identified and characterized; most notably, the vascular endothelial growth factors (VEGFs) family and their receptors, which are the main pro-angiogenic molecules during early development and in pathological conditions such as cancer. Although thyroid is a highly vascularized organ, angiogenic switch in tumors of this organ leads to the formation of a vast network of blood vessels that favors the dissemination of tumor cells to distant organs and results in deterioration of patient conditions. Accordingly, the identification of key angiogenic biomarkers for thyroid cancer can facilitate diagnosis, prognosis and clinical decision-making and also may help to discover targeting factors for effective cancer therapy as well as monitoring response to therapy. Hence, the main purposes of this review are to summarize the types and mechanisms of angiogenesis emphasizing the prominent factors implicated in thyroid cancer angiogenesis.

Sorafenib: key lessons from over 10 years of experience

Introduction: In 2005, sorafenib was the first targeted therapy approved for advanced renal cell carcinoma (RCC), transforming treatment. In hepatocellular carcinoma (HCC), for more than a decade, sorafenib remained the only approved systemic therapy to have demonstrated a survival benefit in first-line unresectable HCC. In 2013, sorafenib was the first targeted agent approved for patients with differentiated thyroid cancer (DTC) refractory to radioactive iodine treatment. Areas covered: This review discusses the development, advances, and challenges associated with sorafenib use in RCC, HCC, and DTC over the past decade. A search was performed on PubMed and key congresses as required, with no time limits. Expert commentary: Sorafenib has had a lasting impact on the therapeutic landscape of RCC, HCC, and DTC, and remains an important treatment option despite a rapidly evolving treatment landscape. Extensive clinical and real-world experience has been invaluable in improving patient management and maximizing benefit from treatment. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in HCC and DTC. We have no doubt that sorafenib will continue to be an important treatment option in the coming years.

Targeted therapies in thyroid cancer: an extensive review of the literature

INTRODUCTION

Patients with progressive, metastatic, RAI-refractory differentiated thyroid cancer (DTC), as well as patients with advanced medullary (MTC) and anaplastic thyroid cancer represent a cohort for which therapeutic options are limited. The recent discoveries in the molecular mechanisms implicated in TC have provided insight of the pathogenesis and progression of disease. In that respect, targeted therapies have emerged as a promising alternative for the treatment of those patients. Areas covered: Tyrosine Kinase Inhibitors (TKIs) have been studied extensively in TC: sorafenib and lenvatinib have been approved by the FDA for the treatment of metastatic, RAI-refractory DTC, while vandetanib and cabozantinib are FDA approved for use in advanced MTC. Moreover, several additional TKIs, multi-targeted or specific, are currently under investigation in TC. The current manuscript provides an extensive review of the literature regarding targeted therapies in TC including the rationale behind their use, the clinical trials and an expert opinion on their use. Literature in English appearing at PubMed was thoroughly reviewed, especially manuscripts of the last 5 years. Expert commentary: Patients with advanced, progressive, metastatic TC should be evaluated for enrollment in a clinical trial or should be placed on treatment with one of the FDA- and EMA- approved agents.

Sorafenib: 10 years after the first pivotal trial

Sorafenib is an oral multikinase inhibitor with anticancer activity against a wide spectrum of cancers. It is currently approved for the treatment of patients with hepatocellular carcinoma, advanced renal cell carcinoma or progressive, locally advanced or metastatic differentiated thyroid carcinoma. In this review, we present a number of studies that investigated the efficacy and safety of sorafenib in these settings. We also discuss the perspectives on the use of this molecule, including the role of sorafenib as comparator for the development of new drugs, the combination of sorafenib with additional therapies (such as transarterial chemoembolization for hepatocellular carcinoma) and the use of this treatment in several other advanced refractory solid tumors.

The Importance of Caveolin-1 as Key-Regulator of Three-Dimensional Growth in Thyroid Cancer Cells Cultured under Real and Simulated Microgravity Conditions

We recently demonstrated that the CAV1 gene was down-regulated, when poorly differentiated thyroid FTC-133 cancer cells formed spheroids under simulated microgravity conditions. Here, we present evidence that the caveolin-1 protein is involved in the inhibition of spheroid formation, when confluent monolayers are exposed to microgravity. The evidence is based on proteins detected in cells and their supernatants of the recent spaceflight experiment: "NanoRacks-CellBox-Thyroid Cancer". The culture supernatant had been collected in a special container adjacent to the flight hardware incubation chamber and stored at low temperature until it was analyzed by Multi-Analyte Profiling (MAP) technology, while the cells remaining in the incubation chamber were fixed by RNAlater and examined by mass spectrometry. The soluble proteins identified by MAP were investigated in regard to their mutual interactions and their influence on proteins, which were associated with the cells secreting the soluble proteins and had been identified in a preceding study. A Pathway Studio v.11 analysis of the soluble and cell-associated proteins together with protein kinase C alpha (PRKCA) suggests that caveolin-1 is involved, when plasminogen enriched in the extracellular space is not activated and the vascular cellular adhesion molecule (VCAM-1) mediated cell-cell adhesion is simultaneously strengthened and activated PRKCA is recruited in caveolae, while the thyroid cancer cells do not form spheroids.

Common Effects on Cancer Cells Exerted by a Random Positioning Machine and a 2D Clinostat

In this study we focused on gravity-sensitive proteins of two human thyroid cancer cell lines (ML-1; RO82-W-1), which were exposed to a 2D clinostat (CLINO), a random positioning machine (RPM) and to normal 1g-conditions. After a three (3d)- or seven-day-culture (7d) on the two devices, we found both cell types growing three-dimensionally within multicellular spheroids (MCS) and also cells remaining adherent (AD) to the culture flask, while 1g-control cultures only formed adherent monolayers, unless the bottom of the culture dish was covered by agarose. In this case, the cytokines IL-6 and IL-8 facilitated the formation of MCS in both cell lines using the liquid-overlay technique at 1g. ML-1 cells grown on the RPM or the CLINO released amounts of IL-6 and MCP-1 into the supernatant, which were significantly elevated as compared to 1g-controls. Release of IL-4, IL-7, IL-8, IL-17, eotaxin-1 and VEGF increased time-dependently, but was not significantly influenced by the gravity conditions. After 3d on the RPM or the CLINO, an accumulation of F-actin around the cellular membrane was detectable in AD cells of both cell lines. IL-6 and IL-8 stimulation of ML-1 cells for 3d and 7d influenced the protein contents of ß₁-integrin, talin-1, Ki-67, and beta-actin dose-dependently in adherent cells. The ß₁-integrin content was significantly decreased in AD and MCS samples compared with 1g, while talin-1 was higher expressed in MCS than AD populations. The proliferation marker Ki-67 was elevated in AD samples compared with 1g and MCS samples. The ß-actin content of R082-W-1 cells remained unchanged. ML-1 cells exhibited no change in ß-actin in RPM cultures, but a reduction in CLINO samples. Thus, we concluded that simulated microgravity influences the release of cytokines in follicular thyroid cancer cells, and the production of ß₁-integrin and talin-1 and predicts an identical effect under real microgravity conditions.

The Immune Interplay between Thyroid Papillary Carcinoma and Hepatic Fibrosis

BACKGROUND

A high prevalence of thyroid papillary cancer was reported in hepatitis-C-virus (HCV) positive patients. However, the mechanistic role of hepatic-fibrosis in thyroid malignancy progressions is still unclear.

AIM

We aimed to study the immune-modulatory interactions between thyroid papillary carcinoma and hepatic-fibrosis.

METHODS

Hepatic-fibrosis was induced in nude-nu-male mice by intra-peritoneal administration of carbon-tetrachloride. To induce thyroid-tumor, a thyroid papillary carcinoma cell line (NPA) was injected subcutaneously in the backs. Fibrotic profile was estimated by α-smooth-muscle-actin (αSMA) expression in liver tissue extracts using western-blots and RT-PCR. Intra-hepatic NK cells were isolated and stained for NK activity (CD107a) by flow cytometry. Liver histopathology (H&E staining), thyroid tumor mass and serum alanine aminotransferase (ALT), serum vascular endothelial growth factor (VEGF) and free-T4 levels were also assessed.

RESULTS

Ex-vivo: NPA cells were co-cultured with intra-hepatic NK cells isolated from fibrotic mice with/without the tumor were analyzed for CFSE-proliferations. Both tumor groups (with/without hepatic-fibrosis) excreted higher serum free T4 levels. Hepatic-fibrosis increased tumor weight and size and serum free-T4 levels. In addition, tumor induction increased liver injury (both hepatic-fibrosis, necro-inflammation and serum ALT levels). In addition, tumor-bearing animals with hepatic-fibrosis had increased NK activity. NPA tumor-bearing animals increased fibrosis in spite of increased NK activity; probably due to a direct effect through increased serum free-T4 excretions. Serum VEGF levels were significantly increased in the fibrotic- bearing tumor groups compared to the non-fibrotic groups. In-vitro, NK cells from fibrotic tumor-bearing animals reduced proliferation of NPA cells. This decrease is attributed to increase NK cells activity in the fibrotic animals with the NPA tumors.

CONCLUSIONS

Our results propose that NK cells although were stimulated in advanced fibrosis with tumor, they lost their anti-tumor and anti-fibrotic activity probably due to secretions of T4 and VEFG and may explain increased risk of thyroid tumors in chronic HCV patients.

miR-145 suppresses thyroid cancer growth and metastasis and targets AKT3

The expression and function of miR-145 in thyroid cancer is unknown. We evaluated the expression and function of miR-145 in thyroid cancer and its potential clinical application as a biomarker. We found that the expression of miR-145 is significantly downregulated in thyroid cancer as compared with normal. Overexpression of miR-145 in thyroid cancer cell lines resulted in: decreased cell proliferation, migration, invasion, VEGF secretion, and E-cadherin expression. miR-145 overexpression also inhibited the PI3K/Akt pathway and directly targeted AKT3. In vivo, miR-145 overexpression decreased tumor growth and metastasis in a xenograft mouse model, and VEGF secretion. miR-145 inhibition in normal primary follicular thyroid cells decreased the expression of thyroid cell differentiation markers. Analysis of indeterminate fine-needle aspiration samples showed miR-145 had a 92% negative predictive value for distinguishing benign from malignant thyroid nodules. Circulating miR-145 levels were significantly higher in patients with thyroid cancer and showed a venous gradient. Serum exosome extractions revealed that miR-145 is secreted. Our findings suggest that miR-145 is a master regulator of thyroid cancer growth, mediates its effect through the PI3K/Akt pathway, is secreted by the thyroid cancer cells, and may serve as an adjunct biomarker for thyroid cancer diagnosis.

Cisplatin based chemotherapy in patients with advanced differentiated thyroid carcinoma refractory to I131 treatment

Purpose:

The purpose of the study was to evaluate the activity and toxicity of cisplatin based chemotherapy in patients with advanced differentiated thyroid cancer refractory to radioactive iodine (I131).

Patients and Methods:

We retrospectively reviewed the records of 20 patients with advanced thyroid cancer treated with cyclophosphamide 500 mg/m² on day 1, doxorubicin 50 mg/m² day 1 and cisplatin 50 mg/m² day 1 of a 21 days cycle community-acquired pneumonia (CAP) or the same regimens without cyclophosphamide adriamycin and Platinum (AP).

Results:

Median age of patients was 65 years (range 54-80). The majority of patients had lung metastases (60%). 4 (20%) patients achieved a partial response. Stable disease was achieved in 6 (30%) patients. Overall clinical response was 50%. Mean follow-up time was 8 months (range 4-17). Mean progression free survival was 6 months (range 3-12). Mean overall survival was 9 months (range 4-17). Patients with partial remission had a mean time to disease progression of 9 months. 4 (20%) patients had Grade 3 or 4 neutropenia. One patient had febrile neutropenia. Mild neuropathy was recorded in 5 (25%) of patients. There were no treatment related deaths.

Conclusion:

The combination of CAP is active in the treatment of advanced thyroid cancer with tolerable toxicity. This regimen may still be used in patients who could not be treated with targeted therapy or combined with antiangiogenic drugs in future studies.

VEGF and GM-CSF levels in nodular thyroid diseases

VEGF is a specific mitogen for endothelial cells. GM-CSF is a key player in the regulation of steady-state functions. The aim of this study was to evaluate VEGF and GM-CSF levels in thyroid nodules >1 cm, which are negative for malignancy with fine needle aspiration biopsy. Age, serum VEGF, GM-CSF, TSH, fT3, fT4, anti-TG, anti-TPO, thyroid size, and thyroid volume were compared between 41 female patients and 20 healthy female volunteers. This study was performed with 41 female patients who were euthyroid and whose nodules were benign. Twenty healthy female volunteers were enrolled as the control group. VEGF and GM-CSF were assayed by ELISA; TSH, fT3, and fT4 were detected by electrochemiluminescence method and anti-TPO and anti-TG were detected by competitive immunoassay method. Only thyroid volume and anti-TG levels were significantly different between the two groups (p < 0.007 and p < 0.026, respectively). Other parameters including VEGF and GM-CSF were not significantly different. VEGF has a weak positive correlation only with anti-TPO levels in the patient group (r = 0.325, p = 0.036). There was a weak positive correlation between anti-TPO and anti-TG (r = 0.388, p = 0.007). There was a positive correlation between nodule size and thyroid volume (r = 0.464, p = 0.015). GM-CSF was not correlated with any parameters. VEGF and GM-CSF were not found to be increased in euthyroid patients with benign nodules and they do not seem to play a role in development of simple nodular goiter.

Development of skin hypopigmentation in a patient with metastatic papillary carcinoma thyroid treated with Sorafenib

BACKGROUND

Sorafenib can be considered as the effective option of treatment in patients with metastatic radioiodine refractory differentiated thyroid cancers. The cutaneous manifestations of Sorafenib include rash, desquamation, hand foot skin reactions, pruritus, alopecia and erythema. We report the first case of hypopigmentation related to sorafenib therapy.

CASE PRESENTATION

We report the case of a middle aged gentleman with metastatic papillary carcinoma of thyroid diagnosed in 2005. He was managed with total thyroidectomy, radioactive iodine and TSH suppressive therapy. Despite receiving radioactive iodine 530 mci cumulative dose, patient had persistant disease with lung metastasis. Therefore a TKI, sorafenib, was started. He developed hypopigmentation of the skin more prominent on face six weeks after starting sorafenib treatment.He also developed diarrhea, desquamation of hands and feet, hair loss over scalp, eye brows and moustache. Sorafenib treatment was discontinued. His diarrhea stopped in one week and after four weeks his skin became normalized whereas he regained his hairs in six weeks.

CONCLUSION

To our knowledge, hypopigmentation in our patient appears to be the first reported of its kind in the literature to date. Sorafenib is used in Renal cell carcinoma, Hepatcellular carcinoma and radioactive iodine refractory thyroid carcinoma therefore it is very important to be aware of hypopigmentation as a potential side effect for both physicians and patients.

Changes and prognostic value of serum vascular endothelial growth factor in patients with differentiated thyroid cancer

OBJECTIVE

To evaluate the changes and the prognostic value of serum vascular endothelial growth factor (VEGF) in patients with differentiated thyroid cancer (DTC).

SUBJECTS AND METHODS

A total of 79 patients with DTC and 30 healthy individuals were divided into four groups: (1) a healthy control group (n = 30); (2) DTC without recurrence (n = 35; 23 papillary, 12 follicular); (3) DTC with local recurrence (n = 24; 15 papillary, 9 follicular), and (4) DTC with lung metastasis (n = 20; 13 papillary, 7 follicular). Serum VEGF and thyroglobulin levels were measured in all patients.

RESULTS

Serum levels of VEGF were significantly higher in the lung metastasis group than in the other three groups (p < 0.05). Serum thyroglobulin concentration positively correlated with VEGF expression (r = 0.8678, p < 0.001) in patients with thyroid cancer recurrence. Multivariate Cox regression analysis showed that clinical staging (OR = 1.851, 95% CI 1.04-3.47; p = 0.038), noncompliance with postoperative thyroxin replacement therapy (OR = 1.935, 95% CI 1.03-3.65; p = 0.042) and postoperative levels of thyroglobulin (OR = 1.892, 95% CI 1.01-3.56, p = 0.032) were independent predictors for thyroid cancer recurrence. Every additional 100 ng/l of serum VEGF levels increased the risk of thyroid cancer recurrence by 20.3%; but this did not reach statistical significance (OR = 1.203, 95% CI 0.95-1.52; p = 0.125).

CONCLUSIONS

Serum VEGF increased in patients with recurrent thyroid cancer following surgical therapies. The predictive value of serum VEGF requires further investigation.

Radioiodine therapy in benign thyroid diseases: effects, side effects, and factors affecting therapeutic outcome

Radioiodine ((131)I) therapy of benign thyroid diseases was introduced 70 yr ago, and the patients treated since then are probably numbered in the millions. Fifty to 90% of hyperthyroid patients are cured within 1 yr after (131)I therapy. With longer follow-up, permanent hypothyroidism seems inevitable in Graves' disease, whereas this risk is much lower when treating toxic nodular goiter. The side effect causing most concern is the potential induction of ophthalmopathy in predisposed individuals. The response to (131)I therapy is to some extent related to the radiation dose. However, calculation of an exact thyroid dose is error-prone due to imprecise measurement of the (131)I biokinetics, and the importance of internal dosimetric factors, such as the thyroid follicle size, is probably underestimated. Besides these obstacles, several potential confounders interfere with the efficacy of (131)I therapy, and they may even interact mutually and counteract each other. Numerous studies have evaluated the effect of (131)I therapy, but results have been conflicting due to differences in design, sample size, patient selection, and dose calculation. It seems clear that no single factor reliably predicts the outcome from (131)I therapy. The individual radiosensitivity, still poorly defined and impossible to quantify, may be a major determinant of the outcome from (131)I therapy. Above all, the impact of (131)I therapy relies on the iodine-concentrating ability of the thyroid gland. The thyroid (131)I uptake (or retention) can be stimulated in several ways, including dietary iodine restriction and use of lithium. In particular, recombinant human thyrotropin has gained interest because this compound significantly amplifies the effect of (131)I therapy in patients with nontoxic nodular goiter.

Radioactive iodine-refractory differentiated thyroid cancer: unmet needs and future directions

Approximately 90% of thyroid cancers are differentiated (DTCs) and have papillary, follicular or Hürthle cell morphology. Although treatment with surgery and radioactive iodine (I-131; RAI), as appropriate, is associated with significant cure rates and survival benefits, clonal disease progression with development of refractoriness to RAI poses a major therapeutic challenge in about 15% of patients. Traditional chemotherapeutic agents are relatively ineffective and are associated with significant toxicities. Molecular studies have demonstrated that the development and progression of DTC are associated with a series of consistent abnormalities in pathways such as MAPK/ERK and PI3/Akt, which govern cellular growth, proliferation, apoptosis and angiogenesis. Small molecular inhibitors that target these pathogenic pathways, without many of the impairments associated with cytotoxic chemotherapy, have demonstrated efficacy in a variety of malignancies, including renal cell carcinoma, hepatocellular carcinoma, non-small-cell lung cancer and chronic myelogenous leukemia. Several targeted therapeutic agents are in development for the treatment of RAI-refractory DTC. Sorafenib and lenvatinib are being studied in placebo-controlled Phase III trials based on encouraging efficacy results observed in single-arm Phase II studies.

Vandetanib in locally advanced or metastatic differentiated thyroid cancer: a randomised, double-blind, phase 2 trial

BACKGROUND

No effective standard treatment exists for patients with radioiodine-refractory, advanced differentiated thyroid carcinoma. We aimed to assess efficacy and safety of vandetanib, a tyrosine kinase inhibitor of RET, VEGFR and EGFR signalling, in this setting.

METHODS

In this randomised, double-blind, phase 2 trial, we enrolled adults (aged ≥18 years) with locally advanced or metastatic differentiated thyroid carcinoma (papillary, follicular, or poorly differentiated) at 16 European medical centres. Eligible patients were sequentially randomised in a 1:1 ratio with a standard computerised scheme to receive either vandetanib 300 mg per day (vandetanib group) or matched placebo (placebo group), balanced by centre. The primary endpoint was progression-free survival (PFS) in the intention-to-treat population based on investigator assessment. This study is registered with ClinicalTrials.gov, number NCT00537095.

FINDINGS

Between Sept 28, 2007, and Oct 16, 2008, we randomly allocated 72 patients to the vandetanib group and 73 patients to the placebo group. By data cutoff (Dec 2, 2009), 113 (78%) patients had progressed (52 [72%] patients in the vandetanib group and 61 [84%] in the placebo group) and 40 (28%) had died (19 [26%] patients in the vandetanib group and 21 [29%] in the placebo group). Patients who received vandetanib had longer PFS than did those who received placebo (hazard ratio [HR] 0·63, 60% CI 0·54-0·74; one-sided p=0·008): median PFS was 11·1 months (95% CI 7·7-14·0) for patients in the vandetanib group and 5·9 months (4·0-8·9) for patients in the placebo group. The most common grade 3 or worse adverse events were QTc prolongation (ten [14%] of 73 patients in the vandetanib group vs none in the placebo group), diarrhoea (seven [10%] vs none), asthenia (five [7%] vs three [4%]), and fatigue (four [5%] vs none). Two patients in the vandetanib group and one in the placebo group died from treatment-related serious adverse events (haemorrhage from skin metastases and pneumonia in the vandetanib group and pneumonia in the placebo group).

INTERPRETATION

Vandetanib is the first targeted drug to show evidence of efficacy in a randomised phase 2 trial in patients with locally advanced or metastatic differentiated thyroid carcinoma. Further investigation of tyrosine-kinase inhibitors in this setting is warranted.

FUNDING

AstraZeneca.

Differentiated thyroid cancers: a comprehensive review of novel targeted therapies

Differentiated thyroid carcinoma (DTC) accounts for more than 90% of new thyroid cancer diagnoses, and includes papillary, follicular and Hürthle cell carcinoma. The prognosis for the vast majority of individuals diagnosed with DTC is excellent, with current treatment that includes surgery, radioactive iodine ablation and postoperative thyroid-stimulating hormone suppression. Unfortunately, the small proportion of individuals who develop radioactive iodine-resistant recurrent disease have few treatment options, and the vast majority will eventually die from their disease. Recently, several novel targets for anticancer agents have been identified and offer new hope for thyroid cancer patients diagnosed with progressive disease. In addition to targeting genes commonly altered in thyroid cancer, which include mutations in BRAF, RAS and RET, proangiogenic growth factor receptors and the sodium-iodide symporter have also been targeted. Several clinical trials evaluating tyrosine kinase and angiogenesis inhibitors for treatment of individuals diagnosed with metastatic or treatment-refractory DTC are currently underway. The objective of this review is to evaluate recent clinical trials that have studied novel targeted drugs for treatment of DTC.

Thyroid cancer: pathogenesis and targeted therapy

Therapeutic options for advanced, unresectable radioiodine-resistant thyroid cancers have historically been limited. Recent progress in understanding the pathogenesis of the various subtypes of thyroid cancer has led to increased interest in the development of targeted therapies, with potential strategies including angiogenesis inhibition, inhibition of aberrant intracellular signaling in the MAPK and PI3K/AKT/mTOR pathways, radioimmunotherapy, and redifferentiation agents. On the basis of a recent positive phase III clinical trial, the RET, vascular endothelial growth factor receptor (VEGFR), and epidermal growth factor receptor (EGFR) inhibitor vandetanib has received FDA approval as of April 2011 for use in the treatment of advanced medullary thyroid cancer. Several other recent phase II clinical trials in advanced thyroid cancer have demonstrated significant activity, and multiple other promising therapeutic strategies are in earlier phases of clinical development. The recent progress in targeted therapy is already revolutionizing management paradigms for advanced thyroid cancer, and will likely continue to dramatically expand treatment options in the coming years.

Activity of XL184 (Cabozantinib), an oral tyrosine kinase inhibitor, in patients with medullary thyroid cancer

PURPOSE

XL184 (cabozantinib) is a potent inhibitor of MET, vascular endothelial growth factor receptor 2 (VEGFR2), and RET, with robust antiangiogenic, antitumor, and anti-invasive effects in preclinical models. Early observations of clinical benefit in a phase I study of cabozantinib, which included patients with medullary thyroid cancer (MTC), led to expansion of an MTC-enriched cohort, which is the focus of this article.

PATIENTS AND METHODS

A phase I dose-escalation study of oral cabozantinib was conducted in patients with advanced solid tumors. Primary end points included evaluation of safety, pharmacokinetics, and maximum-tolerated dose (MTD) determination. Additional end points included RECIST (Response Evaluation Criteria in Solid Tumors) response, pharmacodynamics, RET mutational status, and biomarker analyses.

RESULTS

Eighty-five patients were enrolled, including 37 with MTC. The MTD was 175 mg daily. Dose-limiting toxicities were grade 3 palmar plantar erythrodysesthesia (PPE), mucositis, and AST, ALT, and lipase elevations and grade 2 mucositis that resulted in dose interruption and reduction. Ten (29%) of 35 patients with MTC with measurable disease had a confirmed partial response. Overall, 18 patients experienced tumor shrinkage of 30% or more, including 17 (49%) of 35 patients with MTC with measurable disease. Additionally, 15 (41%) of 37 patients with MTC had stable disease (SD) for at least 6 months, resulting in SD for 6 months or longer or confirmed partial response in 68% of patients with MTC.

CONCLUSION

Cabozantinib has an acceptable safety profile and is active in MTC. Cabozantinib may provide clinical benefit by simultaneously targeting multiple pathways of importance in MTC, including MET, VEGFR2, and RET. A global phase III pivotal study in MTC is ongoing (ClinicalTrials.gov number NCT00215605).

Molecular and other novel advances in treatment of metastatic epithelial and medullary thyroid cancers

An understanding of the mutations of the proto-oncogenes and tumor suppressor genes that occur in thyroid cancers should eventually explain the diverse clinical characteristics of these tumors and also direct therapy. Some insights have already emerged in the last decade; some abnormalities in tumor genes are consistently associated with specific clinical and pathologic findings. These genetic abnormalities usually represent somatic mutations in tumors of follicular epithelial origin, as opposed to inherited mutations in medullary thyroid cancers of parafollicular C cells origin because most thyroid tumors are sporadic and not familial. This is different from the multiple endocrine neoplasia syndromes in which the primary tumorigenic gene mutations are inherited. This improved understanding of the molecular basis of these diseases has led to the development of novel targeted therapeutic approaches which will be discussed in this paper.

Treatment with tyrosine kinase inhibitors for patients with differentiated thyroid cancer: the M. D. Anderson experience

OBJECTIVES

Until recently, treatment options for patients with progressive, radioactive iodine-resistant differentiated thyroid cancer (DTC) have been limited. In our clinical practice, we have begun to use sorafenib and sunitinib for patients with progressive DTC who are not able or willing to participate in clinical trials. In this paper, we describe the University of Texas M. D. Anderson Cancer Center's experience with the off-label use of these tyrosine kinase inhibitors for DTC.

METHODS

Adult patients were included if they had a diagnosis of radioactive iodine-refractory DTC, were treated with single agent sorafenib or sunitinib, and had both baseline and at least one follow-up scan for restaging purposes. All imaging data were collected, as well as the TSH-suppressed thyroglobulin (Tg) levels corresponding to each scan date. The primary endpoints were radiographic response and progression-free survival (PFS). Secondary objectives were tissue-specific radiographic responses and correlation of Tg with overall response.

RESULTS

We identified 33 patients from our clinical database. Fifteen patients (nine women, six men) met inclusion criteria, with a median age of 61 yr (range, 38-83 yr). Eight patients had papillary and seven had follicular thyroid carcinoma. Sorafenib was used in 13 and sunitinib in two, including one patient who failed prior sorafenib therapy. All patients had evidence of progressive disease (PD) before start of therapy, with a median PFS of only 4 months. Best response in target lesions was: partial response (PR) in three (20%), stable disease (SD) in nine (60%), and PD in three (20%). Clinical benefit (PR+SD) was 80%. The sunitinib patient previously refractory to sorafenib had a 38% reduction in tumor size. The most noticeable organ-specific response was observed in lung (median change, -22%) compared to lymph nodes (median change, 0%). Pleural disease and nonirradiated bone metastases demonstrated PD. All histological subtypes had similar responses. The median PFS was 19 months. The median overall survival has not yet been reached, but at 2 yr of follow-up, overall survival is 67%. Log Tg correlated with radiographic response (P = 0.0005).

CONCLUSIONS

Sorafenib and sunitinib appear to be effective in patients with widely metastatic, progressive DTC, with most patients achieving SD or PR, despite having PD at baseline. The most noticeable responses occurred in the lungs in contrast with minimal changes in nodal metastases and PD in pleural and nonirradiated bone metastases, suggesting a tissue-specific response to therapy. Log Tg significantly correlated with response to treatment and therefore may have value as a surrogate marker of response.

Expression of hypoxia-inducible factor 1 alpha in thyroid carcinomas

Hypoxia-inducible factor 1 alpha (HIF-1 alpha) is upregulated by hypoxia and oncogenic signalling in many solid tumours. Its regulation and function in thyroid carcinomas are unknown. We evaluated the regulation of HIF-1 alpha and target gene expression in primary thyroid carcinomas and thyroid carcinoma cell lines (BcPAP, WRO, FTC-133 and 8505c). HIF-1 alpha was not detectable in normal tissue but was expressed in thyroid carcinomas. Dedifferentiated anaplastic tumours (ATCs) exhibited high levels of nuclear HIF-1 alpha staining. The HIF-1 target glucose transporter 1 was expressed to a similar level in all tumour types, whereas carbonic anhydrase-9 was significantly elevated in ATCs. In vitro studies revealed a functionally active HIF-1 alpha pathway in thyroid cells with transcriptional activation observed after graded hypoxia (1% O(2), anoxia) or treatment with a hypoxia mimetic cobalt chloride. High basal and hypoxia-induced expression of HIF-1 alpha in FTC-133 cells that harbour a phosphatase and tensin homologue (PTEN) mutation was reduced by introduction of wild-type PTEN. Similarly, pharmacological inhibition of the phosphoinositide 3-kinase (PI3K) pathway using LY294002 inhibited HIF-1 alpha and HIF-1 alpha targets in all cell lines, including those with B-RAF mutations (BcPAP and 8505c). In contrast, the effects of inhibition of the RAF/MEK/extracellular signal-regulated kinase pathway were restricted by environmental condition and B-RAF mutation status. HIF-1 is functionally expressed in thyroid carcinomas and is regulated not only by hypoxia but also via growth factor signalling pathways and, in particular, the PI3K pathway. Given the strong association of HIF-1 alpha with an aggressive disease phenotype and therapeutic resistance, this pathway may be an attractive target for improved therapy in thyroid carcinomas.

Phase II trial of sorafenib in metastatic thyroid cancer

PURPOSE

Based on the pivotal role of Ras-Raf-MAP-ERK signaling and vascular endothelial growth factor (VEGF) in papillary thyroid cancer (PTC), we conducted a phase II clinical trial of sorafenib targeting RAF and VEGF receptor kinases in PTC.

PATIENTS AND METHODS

The primary end point was the objective response rate. Secondary end points included response correlation with serum thyroglobulin (Tg); functional imaging; tumor genotype; and signaling inhibition in tumor biopsies. Using a Simon minimax two-stage design, 16 or 25 chemotherapy-naïve metastatic PTC patients were to be enrolled in arm A (accessible tumor for biopsy). Arm B patients had other subtypes of thyroid carcinoma or prior chemotherapy, and did not require tumor biopsies. Patients received 400 mg orally twice per day of sorafenib. Response was assessed every 2 months using RECIST (Response Evaluation Criteria in Solid Tumors).

RESULTS

Of 41 PTC patients, six patients had a partial response (PR; 15%; 95% CI, 6 to 29) and 23 patients (56%; 95% CI, 40 to 72) had stable disease longer than 6 months. Median duration of PR was 7.5 months (range, 6 to 14). Median progression-free survival was 15 months (95% CI, 10 to 27.5). In 14 (78%) of 18 Tg-assessable PTC patients, Tg declined more than 25%. Common grade 3 adverse events included hand-foot skin reaction, musculoskeletal pain, and fatigue. BRAF mutation was detected in 17 (77%) of 22 PTCs analyzed. Four of 10 paired tumor biopsies from PTC patients showed a reduction in levels of vascular endothelial growth factor receptor phosphorylation, ERK phosphorylation, and in VEGF expression during sorafenib therapy. No PRs were noted among non-PTC patients.

CONCLUSION

Sorafenib is reasonably well-tolerated therapy with clinical and biologic antitumor activity in metastatic PTC.

Receptor tyrosine kinase inhibitors in thyroid cancer

Thyroid cancer is frequently associated with the oncogenic conversion of receptor tyrosine kinases (RTKs) or their downstream signalling molecules. Hence, there is a strong biological rationale for assessing the efficacy of RTK blockade to treat patients who are resistant to or not candidates for treatment with radioactive iodine. The first results of clinical trials based on the use of RTK inhibitors in thyroid cancer patients have recently been published. Here we discuss targeting of specific RTKs as a potential therapeutic strategy for the treatment of thyroid cancer.

New perspectives on the treatment of differentiated thyroid cancer

Even though differentiated thyroid carcinoma is a slow growing and usually curable disease, recurrence occurs in 20-40% and cellular dedifferentiation in up to 5% of cases. Conventional chemotherapy and radiotherapy have just a modest effect on advanced thyroid cancer. Therefore, dedifferentiated thyroid cancer represents a therapeutic dilemma and a critical area of research. Targeted therapy, a new generation of anticancer treatment, is planned to interfere with a specific molecular target, typically a protein that is believed to have a critical role in tumor growth or progression. Since many of the tumor-initiation events have already been identified in thyroid carcinogenesis, targeted therapy is a promising therapeutic tool for advanced thyroid cancer. Several new drugs are currently being tested in in vitro and in vivo studies and some of them are already being used in clinical trials, like small molecule tyrosine kinase inhibitors. In this review, we discuss the bases of targeted therapies, the principal drugs already tested and also options of redifferentiation therapy for thyroid carcinoma.

Relevance of iodine intake as a reputed predisposing factor for thyroid cancer

Iodine is a trace element that is essential for the synthesis of thyroid hormone. Both chronic iodine deficiency and iodine excess have been associated with hypertrophy and hyperplasia of follicular cells, attributed to excessive secretion of TSH. This may be associated to thyroid cancer risk, particularly in women. Experimental studies have documented thyroid cancer induction by elevation of endogenous TSH, although in a small number of animals. Iodine deficiency associated with carcinogenic agents and chemical mutagens will result in a higher incidence of thyroid malignancy. Inadequate low iodine intake will result in increased TSH stimulation, increased thyroid cell responsiveness to TSH, increased thyroid cell EGF-induced proliferation, decreased TGFbeta 1 production and increased angiogenesis, all phenomena related to promotion of tumor growth. Epidemiological studies associating iodine intake and thyroid cancer led to controversial and conflicting results. There is no doubt that introduction of universal iodine prophylaxis in population previously in chronic iodine-deficiency leads to a changing pattern of more prevalent papillary thyroid cancer and declining of follicular thyroid cancer. Also anaplastic thyroid cancer is practically not seen after years of iodine supplementation. Iodine excess has also been indicated as a possible nutritional factor in the prevalence of differentiated thyroid cancer in Iceland, Hawaii and, more recently, in China.

IN CONCLUSION

available evidence from animal experiments, epidemiological studies and iodine prophylaxis has demonstrated a shift towards a rise in papillary carcinoma, but no clear relationship between overall thyroid cancer incidence and iodine intake.

Phase II trial of sorafenib in advanced thyroid cancer

PURPOSE

Given the molecular pathophysiology of thyroid cancer and the spectrum of kinases inhibited by sorafenib, including Raf kinase, vascular endothelial growth factor receptors, platelet-derived growth factor receptor, and RET tyrosine kinases, we conducted an open-label phase II trial to determine the efficacy of sorafenib in patients with advanced thyroid carcinoma.

PATIENTS AND METHODS

Eligible patients with metastatic, iodine-refractory thyroid carcinoma received sorafenib 400 mg orally twice daily. Responses were measured radiographically every 2 to 3 months. The study end points included response rate, progression-free survival (PFS), and best response by Response Evaluation Criteria in Solid Tumors.

RESULTS

Thirty patients were entered onto the study and treated for a minimum of 16 weeks. Seven patients (23%; 95% CI, 0.10 to 0.42) had a partial response lasting 18+ to 84 weeks. Sixteen patients (53%; 95% CI, 0.34 to 0.72) had stable disease lasting 14 to 89+ weeks. Seventeen (95%) of 19 patients for whom serial thyroglobulin levels were available showed a marked and rapid response in thyroglobulin levels with a mean decrease of 70%. The median PFS was 79 weeks. Toxicity was consistent with other sorafenib trials, although a single patient died of liver failure that was likely treatment related.

CONCLUSION

Sorafenib has clinically relevant antitumor activity in patients with metastatic, iodine-refractory thyroid carcinoma, with an overall clinical benefit rate (partial response + stable disease) of 77%, median PFS of 79 weeks, and an overall acceptable safety profile. These results represent a significant advance over chemotherapy in both response rate and PFS and support further investigation of this agent in these patients.

The comparison of serum vascular endothelial growth factor levels between patients with metastatic and non-metastatic thyroid cancer, and patients with nontoxic multinodular goiter

BACKGROUND

One of the important proangiogenic factors involved in the growth of normal and neoplastic tissues is vascular endothelial growth factor (VEGF).

AIM

We hypothesized that serum VEGF concentration would differ between patients with metastatic and non-metastatic thyroid cancer, multinodular goiter, and healthy subjects. We also hypothesized that endogenous TSH stimulation would affect serum VEGF level.

SUBJECTS AND METHODS

The study group consisted of 71 patients (62 females and 9 males), aged 44.9 +/- 12.3 years, with differentiated thyroid cancer (50 papillary, 17 follicular, and 4 oxyphilic), treated in our department during the years 2003-2006. All patients had undergone total or near-total thyroidectomy and radioactive iodine treatment, that had resulted in remission in 59 patients and persistent/recurrent disease in 12 patients. The study included two control groups: 30 patients with nontoxic multinodular goiter and 30 healthy subjects.

RESULTS

Serum VEGF concentrations were significantly higher in patients with distant metastases than those in remission or healthy patients. (423.4 vs 217.6 vs 235.55 pg/ml respectively, P < 0.05). This was not observed in patients with locoregional metastases. During endogenous TSH stimulation, VEGF decreased significantly (215.3 vs 169.6 pg/ml, P < 0.05). Patients with multinodular goiter showed significantly lower VEGF concentrations than the remaining study groups.

CONCLUSIONS

Serum VEGF concentration might be used as an additional marker of thyroid cancer with distant metastases, but its interpretation should be undertaken very cautiously. Endogenous TSH stimulation decreases VEGF levels in patients either with or without thyroid tissue, suggesting that its regulatory effects are through receptors located outside the thyrocytes.

Tumor cytotoxicity and endothelial Rac inhibition induced by TNP-470 in anaplastic thyroid cancer

Anaplastic thyroid carcinoma is an aggressive form of cancer with no treatment. Angiogenesis inhibitors, such as TNP-470, a synthetic derivative of fumagillin, have been shown to reduce tumor size and increase survival in heterotopic animal models of thyroid cancer. Our goals were to determine the effect of TNP-470 on anaplastic thyroid cancer using an orthotopic murine model, to identify the molecular pathways of TNP-470 actions on endothelial cells, and to determine the non-endothelial tumor effects of TNP-470. We injected human anaplastic thyroid carcinoma cells (DRO'90) into the thyroid glands of nude mice. Mice received TNP-470 (30 mg/kg) s.c. for 6 weeks. TNP-470 prolonged survival and reduced liver metastases. TNP-470 had direct cytotoxic effects on anaplastic thyroid carcinoma cells in vitro and in vivo. Paradoxically, TNP-470 increased vascular endothelial growth factor secretion from tumor cells in vitro and in vivo. However, there was no associated increase in tumor microvessel density. In endothelial cells, TNP-470 prevented vascular endothelial growth factor-induced endothelial permeability, intercellular gap formation, and ruffle formation by preventing Rac1 activation.

Influence of L-thyroxine administration on poor-platelet plasma VEGF concentrations in patients with induced short-term hypothyroidism, monitored for thyroid carcinoma

Angiogenesis is a process of new blood vessel development from pre-existing vasculature. It is a crucial process in normal physiology, as well as in several pathological conditions. The vascular endothelial growth factor (VEGF) represents a family of specific endothelial cell mitogens, involved in normal angiogenesis and in tumour development. The aim of the present study was to estimate the influence of L-thyroxine (L-T4) administration on poor-platelet plasma (P-PP) VEGF concentrations in patients with induced short-term hypothyroidism, monitored for differentiated thyroid carcinoma. In the present study, P-PP concentrations of VEGF, thyroglobulin, thyrotropin and free thyroid hormones were investigated in a population of 24 hypothyroid patients, who were withdrawn from L-T4 treatment for 5 weeks and studied before and after 2 months of L-T4 therapy. Only healthy female patients with no evidence of metastasis in whole body scintigraphy were included in the study. They were then compared with 20 healthy control subjects, matched for age, sex and body mass index (BMI). The patients had significantly lower plasma VEGF concentrations before treatment with L-T4 than after administration of that hormone. There was no significant difference in plasma VEGF levels, either between the patients treated with L-T4, and the controls, or between the patients untreated with L-T4, and the controls. Even short-time changes in thyrometabolic profile exert an important influence on P-PP VEGF concentrations, even if there is no thyroid tissue.

Aplidin reduces growth of anaplastic thyroid cancer xenografts and the expression of several angiogenic genes

BACKGROUND

Anaplastic thyroid cancer (ATC) is one of the most aggressive and highly lethal human cancers. Median survival after diagnosis is 4-6 months despite available radiotherapy and chemotherapy. Additional treatments are needed for ATC. Vascular endothelial growth factor (VEGF) is a potent angiogenic stimulus, which is expressed by ATC. Previously, anti-VEGF antibody was used to block VEGF-dependent angiogenesis in ATC xenografts. This treatment induced partial (56%) but not complete tumor regression. Aplidin (APLD) is a marine derived antitumor agent currently in phase II clinical studies. Multiple activities of this compound have been described which likely contribute to its antiproliferative effect. Notably, APLD has been shown to have antiangiogenic properties which include: inhibition of VEGF secretion, reduction in the synthesis of the VEGF receptor (FLT-1), and blockade of matrix metalloproteinase production by endothelial cells. We hypothesized that Aplidin, with its broad spectrum of action and antiangiogenic properties, would be a potentially effective drug against ATC.

METHODS

Thirty BALB/c nu/nu mice were injected with ATC cells (ARO-81, 1 x 10(6)) and allowed to implant for 3 weeks. Animals were randomized to receive daily intraperitoneal injections of vehicle, low dose (0.5 mg/kg/day), or high dose (1.0 mg/kg/day) APLD. After 3 days, the animals were killed and the tumors were removed, weighed, and divided for RNA and protein analyses.

RESULTS

APLD significantly reduced ATC xenograft growth (low dose, 20% reduction, P = 0.01; high dose, 40% reduction, P < 0.001). This was associated with increased levels of apoptosis related proteins polyadenosylribose polymerase 85 (PARP-85, 75% increase, P = 0.024) and caspase 8 (greater than fivefold increase, P = 0.03). APLD treatment was further associated with lost or reduced expression of several genes that support angiogenesis to include: VEGF, hypoxia inducible factor 1(HIF-1), transforming growth factor-beta (TGFbeta), TGFbeta receptor 2 (TGFbetaR2), melanoma growth stimulating factor 1 (GRO1), cadherin, and vasostatin.

CONCLUSIONS

This data supports the hypothesis that APLD may be an effective adjunctive therapy against ATC. The demonstrated molecular impact against angiogenic related genes specifically supports future strategies combining APLD with VEGF interacting agents.

Antivascular Therapy of Human Follicular Thyroid Cancer Experimental Bone Metastasis by Blockade of Epidermal Growth Factor Receptor and Vascular Growth Factor Receptor Phosphorylation

Patients suffering from bone metastases of follicular thyroid carcinoma (FTC) have a poor prognosis because of the lack of effective treatment strategies. The overexpression of epidermal growth factor receptor (EGFR) associated with increased vascularity has been implicated in the pathogenesis of FTC and subsequent bone metastases. We hypothesized that inhibiting the phosphorylation of the EGFR and vascular endothelial growth factor receptor (VEGFR) by AEE788, a dual tyrosine kinase inhibitor of EGFR and VEGFR, in combination with paclitaxel would inhibit experimental FTC bone lesions and preserve bone structure. We tested this hypothesis using the human WRO FTC cell line. In culture, AEE788 inhibited the EGF-mediated phosphorylation of EGFR, VEGFR2, mitogen-activated protein kinase, and Akt in culture. AEE788, alone and in combination with paclitaxel, inhibited cell growth and induced apoptosis. When WRO cells were injected into the tibia of nude mice, tumor and endothelial cells within the lesions expressed phosphorylated EGFR, VEGFR, Akt, and mitogen-activated protein kinase that were inhibited by the oral administration of AEE788. Therapy consisting of orally given AEE788 and i.p. injected paclitaxel induced a high level of apoptosis in tumor-associated endothelial cells and tumor cells with the inhibition of tumor growth in the bone and the preservation of bone structure. Collectively, these data show that blocking the phosphorylation of EGFR and VEGFR with AEE788 combined with paclitaxel can significantly inhibit experimental human FTC in the bone of nude mice.

Role of COX-2, thromboxane A2 synthase, and prostaglandin I2 synthase in papillary thyroid carcinoma growth

The development of papillary thyroid carcinoma is influenced by many factors including genetic alterations, growth factors, and physical agents such as radiation. Arachidonic acid and its derivatives including prostaglandins (PG) and thromboxane along with the enzymes involved in their synthesis have been shown to influence the growth of various tumors. We analyzed the immunoreactivity for cyclooxygenase-2 (COX-2) and mRNA expression levels of the enzymes COX-2, thromboxane A(2) (TXA(2)) synthase, and PGI(2) synthase by RT-PCR in papillary carcinomas and matching normal tissues to determine the role of these enzymes in the development of papillary thyroid carcinomas. A papillary thyroid carcinoma cell line TPC-1 was also studied in vitro to determine the role of the specific COX-2 inhibitor NS-398 on COX-2 and vascular endothelial growth factor-A, since COX-2 also has a role in regulating tumor angiogenesis. RT-PCR analysis showed significant increases in TXA(2) synthase mRNA levels in papillary thyroid carcinomas compared to normal thyroid tissues. Although COX-2 mRNA levels were generally increased in papillary carcinomas, the differences were not statistically significant. There were no significant differences in PGI(2) synthase mRNA levels. COX-2 protein expression was greater in papillary carcinoma compared to normal thyroid tissues; however, the levels were quite variable. In vitro studies with a COX-2 inhibitor, NS-398, showed inhibition of tumor growth along with increased levels of COX-2 and vascular endothelial growth factor-A mRNA expression. These results indicate that specific enzyme levels in the PG synthesis pathway such as TXA(2) synthase are increased in papillary thyroid carcinomas. COX-2 also has a role in papillary thyroid growth, since a specific inhibitor of COX-2 regulates papillary thyroid carcinoma cell proliferation. These results implicate several enzymes in the synthesis of prostanoids as regulators of thyroid papillary carcinoma proliferation and suggest that increased levels of expression of these enzymes may play a role in the pathogenesis of these tumors.

Expanding the Clinical Development of Bevacizumab

Bevacizumab (Avastin; Genentech, Inc.; South San Francisco, CA) is a recombinant, humanized monoclonal antibody to vascular endothelial growth factor, a key regulator of tumor angiogenesis. Bevacizumab demonstrated potent antitumor activity in preclinical models and has also shown biologic activity and clinical benefit in clinical studies. Notably, a randomized, placebo-controlled phase II trial in renal cell carcinoma demonstrated a significantly longer time to tumor progression with bevacizumab monotherapy. Furthermore, in a phase III trial for untreated advanced colorectal cancer, the addition of bevacizumab to chemotherapy led to significantly longer overall survival and progression-free survival times than chemotherapy alone. The clinical development of bevacizumab has been expanded to include confirmatory phase III trials and exploratory phase II trials in a variety of solid tumors and hematologic malignancies. Treatment regimens being examined include bevacizumab alone and in combination with conventional chemotherapy, radiation, immune therapy, and biologically targeted agents.

sFlt-1 gene therapy of follicular thyroid carcinoma

Tumor progression largely depends on blood supply and neovessel formation, and angiogenesis is emerging as a promising target for cancer therapy. Vascular endothelial growth factor (VEGF), a major proangiogenic molecule, stimulates angiogenesis via promoting endothelial proliferation, survival and migration. VEGF has been found to be up-regulated in various types of tumors and to be associated with tumor progression and poor prognosis. Inhibition of VEGF or its signaling pathway has been shown to suppress tumor angiogenesis and tumor growth. In the present study, we tested the antiangiogenic and antitumor effects of soluble VEGF receptor-1 [soluble Flt (sFlt)-1] on the growth of follicular thyroid carcinoma (FTC). We constructed a 293 embryonic kidney cell line (293-Flt1-3d) that expresses sFlt-1, which is composed of the first three extracellular domains of Flt-1. The 293-Flt1-3d cells inhibited the in vitro growth of human umbilical vein endothelial cells in a paracrine manner. The in vivo antitumor and antiangiogenic activities of the 293-Flt1-3d cells were tested. When 293-Flt1-3d cells were inoculated at a site remote to the FTC-133 tumor transplant, the growth of FTC-133 tumors were inhibited by 70.37%, as compared with the control treatment with 293 cells expressing control gene LacZ. Immunohistochemical analysis of microvessel densities in treated tumors demonstrated that 293-Flt1-3d cells robustly suppressed intratumoral angiogenesis. Our data suggest that a mammalian cell-mediated approach could effectively deliver sFlt-1 gene therapy and inhibit tumor angiogenesis and tumor growth.

Regulation of vascular endothelial growth factor expression by insulin-like growth factor I in thyroid carcinomas

Vascular endothelial growth factor (VEGF) produced by tumor cells potently stimulates endothelial cell proliferation and angiogenesis and plays a key role in the pathophysiology of several neoplasias. Hypoxia activates the VEGF promoter via response elements that bind the transcription factors hypoxia-inducible factor-1 alpha (HIF-1 alpha) and activator protein-1 (AP-1). Yet, the paracrine signaling pathways regulating VEGF production and angiogenesis in thyroid cancer have not been fully elucidated. In this study, we, therefore, investigated the regulation of VEGF production by the thyroid carcinoma cell line SW579. We found that IGF-I up-regulated VEGF mRNA expression and protein secretion. Furthermore, transfection of SW579 cells with vector expressing a constitutively active form of Akt, a major mediator of IGF-I signaling, also stimulated VEGF expression. The IGF-I-induced up-regulation of VEGF production was associated with activation of AP-1 and HIF-1 alpha and was abrogated by phosphatidylinositol 3-kinase inhibitors (wortmannin and LY294002); Jun kinase inhibitor (SP600125); HIF-1 alpha antisense oligonucleotide; or geldanamycin, an inhibitor of the heat shock protein 90 molecular chaperone, which regulates the three-dimensional conformation and function of IGF-I-receptor and Akt. These data indicate that IGF-I stimulates VEGF synthesis in thyroid carcinomas in an Akt-dependent pathway via AP-1 and HIF-1 alpha and provide the framework for clinical use of small-molecule inhibitors, including geldanamycin analogs, to abrogate proangiogenic cascades in thyroid cancer.

Antiangiogenic and antitumor effects of endostatin on follicular thyroid carcinoma

Tumor growth and metastasis depend on blood supply and blood vessel formation. Angiogenesis, therefore, represents a promising target for cancer therapy. Endostatin is one of the most potent antiangiogenic factors and has been shown to effectively inhibit angiogenesis and tumor growth in a variety of in vivo models. In this study, we tested the effects of endostatin on xenografted human follicular thyroid carcinoma (FTC) in nude mice. Our result demonstrated that recombinant endostatin significantly inhibited the growth of FTC xenografts. Furthermore, we established an endostatin-expressing FTC cell line (FTC-BmEndo) using retrovirus-mediated gene transfer approach. We found that the in vivo growth of FTC-BmEndo cells was significantly inhibited, compared with the parental FTC cells, whereas both lines grew at the same rate in vitro. High-level expression of endostatin within the FTC-BmEndo tumors was evidenced by immunohistochemical staining, paralleled with a reduced microvessel density. The systemic level of vascular endothelial growth factor was significantly lower in mice bearing the FTC-BmEndo tumors than in those bearing parental FTC tumors. By using two different approaches, namely the recombinant endostatin protein and the gene therapy strategy, our study demonstrated that endostatin could be effective in suppressing the growth of human FTC in immunodeficient mice.